Brain morphology assessed by computed tomography in patients with geriatric depression, patients with degenerative dementia, and normal control subjects

Peripheral and central hearing impairment and their relationship with cognition: a review

Objective: To consider the relationships between both peripheral and central hearing impairment and cognition. Design: Narrative review. Study sample: Numerous studies exploring the relationship between hearing impairment and cognitive function, particularly in an older population. Results: In addition to the well-documented relationship between peripheral hearing loss and cognition highlighted in previous comprehensive reviews, there is also some evidence to suggest that there is a relationship between central hearing impairment and cognition. Further research is required to better understand this relationship and its effects on hearing aid benefit in people with both peripheral hearing loss and central hearing impairment. Conclusions: To fully understand the relationship between hearing impairment and cognitive impairment, not only peripheral but central hearing needs to be considered. Such knowledge could be of benefit in the clinical management of people with both peripheral hearing loss and central hearing impairment.

Total intracranial and lateral ventricle volumes measurement in Alzheimer's disease: A methodological study

Measuring of brain and its compartments' sizes from magnetic resonance (MR) images is an effective way to assess disease progression in neurodegenerative disorders, particularly Alzheimer's disease (AD). The objective of this study was to compare total intracranial volume (TIV) and lateral ventricle volume (LVV) in patients with Alzheimer's disease with those in elderly control subjects, and to compare an automated method (automatic lateral ventricle delineation [ALVIN]) and a manual method (ImageJ). MRI of the brain was performed on 20 patients with Alzheimer's disease and 18 control subjects. The TIV was calculated by a manual method and the LVV was calculated by using two methods: an automated and manual method. We found a significant increase in LVVs in Alzheimer's disease patients compared to control subjects, but no difference in TIV between the two groups. A perfect agreement, with 0.989 (0.973-0.996) intraclass correlation coefficient (ICC) and 0.978 (0.946-0.991) concordance correlation coefficient (CCC), was observed between the manual and automatic lateral ventricle measurements in Alzheimer patients. The results revealed that LVV measure has predictive performance in AD. We demonstrated that ALVIN and ImageJ are both effective in determining lateral ventricular volume, providing an objective tool for quantitative assessment of AD.

Practical one-dimensional measurements of age-related brain atrophy are validated by 3-dimensional values and clinical outcomes: a retrospective study

Background

Age-related brain atrophy has been represented by simple 1-dimensional (1-D) measurements on computed tomography (CT) for several decades and, more recently, with 3-dimensional (3-D) analysis, using brain volume (BV) and cerebrospinal fluid volume (CSFV). We aimed to show that simple 1-D measurements would be associated with 3-D values of age-related atrophy and that they would be related to post-traumatic intracranial hemorrhage (ICH).

Methods

Patients ≥60 years with head trauma were classified with central atrophy (lateral ventricular body width >30 mm) and/or cortical atrophy (sulcus width ≥2.5 mm). Composite atrophy was the presence of central or cortical atrophy. BV and CSFV were computed using a Siemens Syngo workstation (VE60A).

Results

Of 177 patients, traits were age 78.3 ± 10, ICH 32.2 %, central atrophy 39.5 %, cortical atrophy 31.1 %, composite atrophy 49.2 %, BV 1,156 ± 198 mL, and CSFV 102.5 ± 63 mL. CSFV was greater with central atrophy (134.4 mL), than without (81.7 mL, p < 0.001). BV was lower with cortical atrophy (1,034 mL), than without (1,211 mL; p < 0.001). BV was lower with composite atrophy (1,103 mL), than without (1,208 mL; p < 0.001). CSFV was greater with composite atrophy (129.1 mL), than without (76.8 mL, p < 0.001). CSFV÷BV was greater with composite atrophy (12.3 %), than without (6.7 %, p < 0.001). Age was greater with composite atrophy (80.4 years), than without (76.3, p = 0.006). Age had an inverse correlation with BV (p < 0.001) and a direct correlation with CSFV (p = 0.0002) and CSFV÷BV (p < 0.001). ICH was greater with composite atrophy (49.4 %), than without (15.6 %; p < 0.001; odds ratio = 5.3). BV was lower with ICH (1,089 mL), than without (1,188 mL; p = 0.002). CSFV÷BV was greater with ICH (11.1 %), than without (8.7 %, p = 0.02). ICH was independently associated with central atrophy (p = 0.001) and cortical atrophy (p = 0.003).

Conclusions

Simple 1-D measurements of age-related brain atrophy are associated with 3-D values. Clinical validity of these methods is also supported by their association with post-injury ICH. Intracranial 3-D software is not available on many CT scanners and can be cumbersome, when available. Simple 1-D measurements, using the study methodology, are a practical method to objectify the presence of age-related brain atrophy.

Brain Structural Effects of Antidepressant Treatment in Major Depression

Depressive disorder is a very frequent and heterogeneous syndrome. Structural imaging techniques offer a useful tool in the comprehension of neurobiological alterations that concern depressive disorder. Altered brain structures in depressive disorder have been particularly located in the prefrontal cortex (medial prefrontal cortex and orbitofrontal cortex, OFC) and medial temporal cortex areas (hippocampus). These brain areas belong to a structural and functional network related to cognitive and emotional processes putatively implicated in depressive symptoms. These volumetric alterations may also represent biological predictors of response to pharmacological treatment. In this context, major findings of magnetic resonance (MR) imaging, in relation to treatment response in depressive disorder, will here be presented and discussed.

Enhancing synaptic plasticity and cellular resilience to develop novel, improved treatments for mood disorders

There is mounting evidence that recurrent mood disorders - once considered “good prognosis diseases”- are, in fact, often very severe and life-threatening illnesses. Furthermore, although mood disorders have traditionally been conceptualized as neurochemical disorders, there is now evidence from a variety of sources demonstrating regional reductions in central nervous system (CNS) volume, as well as reductions in the numbers and/or sizes ofglia and neurons in discrete brain areas. Although the precise cellular mechanisms underlying these morphometric changes remain to be fully elucidated, the data suggest that mood disorders are associated with impairments of synaptic plasticity and cellular resilience. In this context, it is noteworthy that there is increasing preclinical evidence that antidepressants regulate the function of the glutamatergic system. Moreover, although clearly preliminary, the available clinical data suggest that attenuation of N-methyl-D-aspartate (NMDA) function has antidepressant effects. Recent preclinical and clinical studies have shown that signaling pathways involved in regulating cell survival and cell death are long-term targets for the actions of antidepressant agents. Antidepressants and mood stabilizers indirectly regulate a number of factors involved in cell survival pathways, including cyclic adenosine monophosphate (cAMP) response element binding protein (CREB), brain-derived neurotrophic factor (BDNF), the antiapoptotic protein bcl-2, and mitogen-activated protein (MAP) kinases, and may thus bring about some of their delayed long-term beneficial effects via underappreciated neurotrophic effects. There is much promise for the future development of treatments that more directly target molecules in critical CNS signaling pathways regulating synaptic plasticity and cellular resilience. These will represent improved long-term treatments for mood disorders.

Cerebrospinal fluid space alterations in melancholic depression

Melancholic depression is a biologically homogeneous clinical entity in which structural brain alterations have been described. Interestingly, reports of structural alterations in melancholia include volume increases in Cerebro-Spinal Fluid (CSF) spaces. However, there are no previous reports of CSF volume alterations using automated whole-brain voxel-wise approaches, as tissue classification algorithms have been traditionally regarded as less reliable for CSF segmentation. Here we aimed to assess CSF volumetric alterations in melancholic depression and their clinical correlates by means of a novel segmentation algorithm (‘new segment’, as implemented in the software Statistical Parametric Mapping-SPM8), incorporating specific features that may improve CSF segmentation. A three-dimensional Magnetic Resonance Image (MRI) was obtained from seventy patients with melancholic depression and forty healthy control subjects. Although imaging data were pre-processed with the ‘new segment’ algorithm, in order to obtain a comparison with previous segmentation approaches, tissue segmentation was also performed with the ‘unified segmentation’ approach. Melancholic patients showed a CSF volume increase in the region of the left Sylvian fissure, and a CSF volume decrease in the subarachnoid spaces surrounding medial and lateral parietal cortices. Furthermore, CSF increases in the left Sylvian fissure were negatively correlated with the reduction percentage of depressive symptoms at discharge. None of these results were replicated with the ‘unified segmentation’ approach. By contrast, between-group differences in the left Sylvian fissure were replicated with a non-automated quantification of the CSF content of this region. Left Sylvian fissure alterations reported here are in agreement with previous findings from non-automated CSF assessments, and also with other reports of gray and white matter insular alterations in depressive samples using automated approaches. The reliable characterization of CSF alterations may help in the comprehensive characterization of brain structural abnormalities in psychiatric samples and in the development of etiopathogenic hypotheses relating to the disorders.

Structural neuroimaging studies in major depressive disorder. Meta-analysis and comparison with bipolar disorder

CONTEXT

Although differences in clinical characteristics exist between major depressive disorder (MDD) and bipolar disorder (BD), consistent structural brain abnormalities that distinguish the disorders have not been identified.

OBJECTIVES

To investigate structural brain changes in MDD using meta-analysis of primary studies; assess the effects of medication, demographic, and clinical variables; and compare the findings with those of a meta-analysis of studies on BD.

DATA SOURCES

The MEDLINE, EMBASE, and PsycINFO databases were searched for studies from January 1, 1980, to February 2, 2010.

STUDY SELECTION

Two hundred twenty-five studies that used magnetic resonance imaging or x-ray computed tomography to compare brain structure in patients with MDD with that of controls were included in an online database, and 143 that measured common brain structures were selected for meta-analysis.

DATA EXTRACTION

Twenty-five variables, including demographic and clinical data, were extracted from each study, when available. For the meta-analysis, mean structure size and standard deviation were extracted for continuous variables, and the proportion of patients and controls with an abnormality in brain structure was extracted for categorical variables.

DATA SYNTHESIS

Compared with the structure of a healthy brain, MDD was associated with lateral ventricle enlargement; larger cerebrospinal fluid volume; and smaller volumes of the basal ganglia, thalamus, hippocampus, frontal lobe, orbitofrontal cortex, and gyrus rectus. Patients during depressive episodes had significantly smaller hippocampal volume than patients during remission. Compared with BD patients, those with MDD had reduced rates of deep white matter hyperintensities, increased corpus callosum cross-sectional area, and smaller hippocampus and basal ganglia. Both disorders were associated with increased lateral ventricle volume and increased rates of subcortical gray matter hyperintensities compared with healthy controls.

CONCLUSIONS

The meta-analyses revealed structural brain abnormalities in MDD that are distinct from those observed in BD. These findings may aid investigators attempting to discriminate mood disorders using structural magnetic resonance imaging data.

Temporal lobe atrophy and white matter lesions are related to major depression over 5 years in the elderly

The influence of organic brain changes on the development of depression in the elderly is uncertain. Cross-sectional studies, most often from clinical samples, report associations with brain atrophy and cerebrovascular disease, while longitudinal population studies have given mixed results. Our aim was to investigate whether cortical atrophy and white matter lesions (WMLs) on computed tomography (CT) predict occurrence of depression in the elderly. This is a prospective population-based study with 5-year follow-up. The baseline sample included 525 elderly subjects, aged 70-86 years, without dementia or major depression, with a score on the Mini-Mental State Examination above 25, and without dementia at follow-up. Cortical atrophy and WMLs were evaluated at baseline using CT. The main outcome measure was development of major or minor depression at follow-up according to Diagnostic and Statistical Manual of Mental Disorders, fourth edition, as evaluated using neuropsychiatric examinations and hospital discharge registers. Logistic regression was used to estimate risk. Over the period of 5 years, 20 individuals developed major and 63 minor depression. Presence of temporal lobe atrophy (odds ratio (OR)=2.81, 95% confidence interval (CI) 1.04-7.62) and moderate-to-severe WMLs (OR=3.21, 95% CI 1.00-10.26) independently predicted major, but not minor, depression after controlling for various confounders. Other brain changes did not predict occurrence of depression. Our findings suggest that temporal lobe atrophy and WMLs represent relatively independent and complementary pathways to major depression in the elderly. This may have implications for prevention, as both neurodegeneration and cerebrovascular disease have been related to preventable factors.

Volumetric brain imaging studies in the elderly with mood disorders

Volumetric neuroimaging studies of the elderly with affective disorders provide important insights into the underlying physiology of the illnesses. Advantages of studying the elderly include the ability to make various assessments and obtain a history differentiating subtypes of illness. However, challenges to studying the elderly include the heterogeneity of affective illnesses and confounds of medical comorbidity and medications. Volumetric assessments have provided important information in the neural mechanisms of mood regulation, especially in the overlap of cognitive disorders. This article reviews articles describing findings of volumetric analyses in elderly with unipolar depression and bipolar disorders, and compares and contrasts these findings with the larger volumetric research in affective disorders.

Enhancing neuronal plasticity and cellular resilience to develop novel, improved therapeutics for difficult-to-treat depression

There is growing evidence from neuroimaging and ostmortem studies that severe mood disorders, which have traditionally been conceptualized as neurochemical disorders, are associated with impairments of structural plasticity and cellular resilience. It is thus noteworthy that recent preclinical studies have shown that critical molecules in neurotrophic signaling cascades (most notably cyclic adenosine monophosphate [cAMP] response element binding protein, brain-derived neurotrophic factor, bcl-2, and mitogen activated protein [MAP] kinases) are long-term targets for antidepressant agents and antidepressant potentiating modalities. This suggests that effective treatments provide both trophic and neurochemical support, which serves to enhance and maintainnormal synaptic connectivity, thereby allowing the chemical signal to reinstate the optimal functioning of critical circuits necessary for normal affective functioning. For many refractory patients, drugs mimicking "traditional" strategies, which directly or indirectly alter monoaminergic levels, may be of limited benefit. Newer "plasticity enhancing" strategies that may have utility in the treatment of refractory depression include N-methyl-D-aspartate antagonists, alpha-amino-3-hydroxy-5-methylisoxazole propionate (AMPA) potentiators, cAMP phosphodiesterase inhibitors, and glucocorticoid receptor antagonists. Small-molecule agents that regulate the activity f growth factors, MAP kinases cascades, and the bcl-2 family of proteins are also promising future avenues. The development of novel, nonaminergic-based therapeutics holds much promise for improved treatment of severe, refractory mood disorders.

Volumetric brain imaging findings in mood disorders

Volumetric neuroimaging is increasingly being used by researchers of affective disorders to assess potential involvement of different brain structures in mood regulation and to test neuroanatomic models of mood disorders. In unipolar depression, findings suggest abnormalities in the frontal lobe (particularly the subgenual prefrontal cortex), basal ganglia (particularly the caudate and putamen), cerebellum, and hippocampus/amygdala complex. In bipolar disorder, abnormalities in the third ventricle, frontal lobe, cerebellum, and possibly the temporal lobe are noted. We review the findings for the various regions of the brain, and discuss the implications on the understanding of mood disorders. Directions for future research in volumetric imaging is then discussed.

Anatomical MRI findings in mood and anxiety disorders

OBJECTIVE

In vivo structural magnetic resonance imaging (MRI) studies have evaluated the brain anatomy of various psychiatric disorders, allowing the investigation of putative abnormal brain circuits possibly involved in the patophysiology of psychiatric disorders. Here we reviewed the structural MRI literature in mood and anxiety disorders.

METHODS

All anatomical MRI studies evaluating mood and anxiety disorder patients were identified through a comprehensive Medline search conducted for the period from 1966 to January 2002, and a manual search of bibliographic cross-referencing complemented the Medline search.

RESULTS

Differential patterns of anatomical brain abnormalities appear to be involved in subtypes of mood disorders, with hippocampus and basal ganglia being abnormal in unipolar disorder, and amygdala and cerebellum in bipolar disorders, suggesting that these two mood disorders are biologically distinct. As for anxiety disorders, orbital frontal regions and basal ganglia have been reported to be anatomically abnormal in obsessive-compulsive disorder, temporal lobe was found to be abnormally reduced in panic disorder, and abnormal hippocampus shrinkage was shown in posttraumatic stress disorder.

CONCLUSIONS

The structural MRI findings reviewed here suggest abnormalities in specific brain regions participating in proposed neuroanatomic models possibly involved in the pathophysiology of mood disorders and anxiety disorders. Nonetheless, available MRI studies have suffered from limitations related to relatively small patient samples and involvement of medicated patients, and were largely cross-sectional investigations. Therefore, longitudinal MRI studies involving more sizeable samples of drug-free patients, patients at first episode of illness or at high risk for mood or anxiety disorders, associated to genetic studies, are likely to be extremely valuable to separate state from trait brain abnormalities and to characterize further the pathophysiology of these disorders.

CSF spaces of the Sylvian fissure region in severe melancholic depression

The Sylvian fissure region gathers lateral frontotemporal cortices and subcortical structures that are frequently disturbed in patients with mood disorders. We have investigated possible CSF space changes in this brain region in severe melancholic depression. Fifty-seven patients and 37 control subjects received three-dimensional MRI. CSF volumes were obtained for cerebral CSF, lateral ventricles, and both Sylvian fissure regions. As a group, patients showed a significant CSF space enlargement that was prominent around the Sylvian fissure, particularly in the left hemisphere. Likewise, evident leftward asymmetry was more frequent in the patient group (patients 31.6%, controls 2.7%). The combination of CSF space enlargement and the pattern of Sylvian CSF asymmetry predicted the patient condition with 62.2% specificity and 82.5% sensitivity. We conclude that, in the context of a broad severity spectrum of imaging alterations in severe melancholic depression, asymmetrical CSF space enlargement may be evident in the Sylvian fissure region.

Prefrontal enlargement of CSF spaces in agoraphobia: a qualitative CT-scan study

1. This CT study was designed to assess brain morphology in 21 patients with agoraphobia and 21 normal control subjects matched for age and sex. 2. Internal and external CSF spaces were evaluated by qualitative assessment on a 3-point scale (normal, questionable, abnormal). 3. Patients showed bilateral enlargement of prefrontal CSF spaces (p < .05). The rating abnormal" was given in the left hemisphere to 6 (28.6%) of the patients, to 4 (19%) of the patients in the right hemisphere, but to none (0%) of the normal controls. 4. These findings suggest that alterations in brain morphology are involved in the etiology of agoraphobia.

Changes in CSF spaces differ in endogenous and neurotic depression. A planimetric CT scan study

Regional planimetric measurements of internal and external CSF spaces were performed in CT scans of 23 patients with endogenous depression (ICD 9, 296.1) and 28 patients with neurotic depression (ICD 9, 300.4) as compared to 56 control individuals without neuropsychiatric disorder. In female patients with endogenous depression, but not in men, the bilateral upper cortical sulci were widened, especially in the frontal regions, and the third ventricle was enlarged. In contrast, the female neurotic depressed group showed no enlargement of CSF spaces, but a narrowing of the Sylvian fissure and of the basal frontal lobe reaching level of significance in the right fronto-temporal region (P = 0.005). No narrowing of CSF spaces was observed in women with endogenous depression. A discriminant analysis of significantly changed CSF regions resulted in a correct classification in 82.4% of depressed women in either the endogenous or the neurotic group. Determination of divergent types of brain pathology might prove as a useful tool in validating the differential classification of these two main subtypes of affective disorders.

Time course of cerebral ventricular enlargement in schizophrenia supports the hypothesis of its neurodevelopmental nature

In the absence of direct and conclusive data demonstrating the 'neurodevelopmental hypothesis' of schizophrenia, several neuromorphological findings provide relevant clues in support of it. In this paper, we review a number of results obtained by our group in this area of research. In particular, the demonstration of stability of cerebral ventricular dimensions both in chronic schizophrenia and around the onset of the disease, and that of an identical effect of ageing on this morphological feature in large samples of patients and controls, strongly support the neurodevelopmental nature of brain pathomorphology in schizophrenia.

Quantitative magnetic resonance imaging in geriatric depression and primary degenerative dementia

Quantitative magnetic resonance imaging (MRI) was used to investigate volumes of different brain structures in 19 patients with late-onset major depression (DSM-III-R), 27 patients with Alzheimer's disease (NINCDS-ADRDA criteria) and 13 age matched controls. 3-D MRI sequences were acquired using a Siemens 1.5 T scanner. Whole brain volume, CSF volume, volume of the frontal and temporal lobes and the volume of the amygdala-hippocampus complex were assessed using the software NMR Win. Compared to the controls, depressed patients showed a significantly lower whole brain volume and a significantly higher CSF volume, whereas volumes of the frontal and temporal lobes as well as the amygdala-hippocampus complex volumes were not significantly decreased. In addition, depressed patients exhibited a higher ventricle-brain ratio suggesting a higher degree of central atrophy compared to healthy individuals. In contrast, Alzheimer patients showed significantly lower volumes than depressed patients and controls with respect to all volumetric parameters. Although the findings indicate the presence of brain atrophy in patients with late-onset depression, the pattern of volumetric changes in these patients differs markedly from that observed in patients with primary degenerative dementia.

The anatomy of mood disorders--review of structural neuroimaging studies

The structural neuroimaging findings in mood disorders were reviewed, to evaluate evidence for a neuroanatomic model of pathophysiology, involving the prefrontal cortex, the basal ganglia, the amygdala-hippocampus complex, thalamus, and connections among these structures. Global atrophy is not consistently found. The best replicated finding is an increased rate of white matter and periventricular hyperintensities. A smaller frontal lobe, cerebellum, caudate, and putamen appear present in unipolar depression. A larger third ventricle, and smaller cerebellum and perhaps temporal lobe appear present in bipolar disorder. These localized structural changes involve regions that may be critical in the pathogenesis of mood disorders. Generalized and localized anatomic alterations may be related to age or vascular disease. The clinical and biological correlates of these changes need to be investigated to allow development of a more complete model of pathophysiology of mood disorders.